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Title:
UNDERSEA HYDROTHERMAL ENERGY TRANSFER SYSTEM WITH REMOVABLE REDUNDANT UNITS
Document Type and Number:
WIPO Patent Application WO/2020/082003
Kind Code:
A1
Abstract:
An undersea hydrothermal energy transfer system including a structure having a number of underwater installation bays, the structure adapted to be installed in an undersea location. A number of redundant units, where each of the redundant units is adapted to be installed into the structure through a separate one of the underwater installation bays. Each of the redundant units is located to receive hydrothermally heated fluid from an undersea hydrothermal source.

Inventors:
BURKE TIMOTHY (US)
Application Number:
PCT/US2019/057040
Publication Date:
April 23, 2020
Filing Date:
October 18, 2019
Export Citation:
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Assignee:
BURKE TIMOTHY (US)
International Classes:
F03G7/05; F03G4/00; F03G4/06; F03G7/00; F03G7/04
Foreign References:
US4350014A1982-09-21
US20150260464A12015-09-17
US20090013690A12009-01-15
US20120080164A12012-04-05
US20090217664A12009-09-03
US20140096519A12014-04-10
Attorney, Agent or Firm:
LEONE, George (US)
Download PDF:
Claims:
Claims

What is claimed is:

1 . An undersea hydrothermal energy transfer system comprising:

a structure having a plurality of underwater installation bays, the structure adapted to be installed in an undersea location;

a plurality of redundant units, wherein each of the plurality of redundant units is adapted to be installed into a separate one of the plurality of underwater installation bays; and

wherein each of the plurality of redundant units is located to receive hydrothermally heated fluid from at least one undersea hydrothermal source.

2. The system of claim 1 wherein each of the plurality of redundant units is selected from the group consisting of a heat engine, a condenser, an evaporator, a generator, a hydrothermal to mechanical energy converter, a hydrothermal to electrical energy converter, a hydrothermal to mechanical energy converter engine employing a Carnot heat engine cycle, a Rankine closed cycle system, an organic Rankine cycle, a Stirling cycle engine, an Erickson cycle engine, a Stoddard engine and combinations thereof.

3. The system of claim 1 wherein the evaporator and condenser are fluidly coupled to operate together as a heat engine.

4. The system of claim 1 wherein the at least one undersea hydrothermal source comprises a thermal energy field integrating a plurality of undersea thermal vents.

5. The system of claim 4 wherein the one or more undersea hydrothermal energy sources are each coupled to a conduit for fluidly transmitting thermally heated fluid to a main conduit or plurality of conduits.

6. The system of claim 5 wherein main conduit or plurality of conduits are coupled to the plurality of redundant units.

7. The system of claim 1 wherein each of the plurality of redundant units transmits energy to an above surface or on shore hydrothermal powerplant.

8. The system of claim 7 wherein the above surface or on shore hydrothermal powerplant includes an energy converter for converting heat energy to electrical energy.

9. The system of claim 8 wherein the electrical energy is stored or transmitted.

10. An undersea hydrothermal energy transfer system comprising:

a structure including a plurality of installation ports, wherein the structure is adapted to be installed in an undersea location;

a plurality of redundant powerplant units wherein each redundant powerplant unit is installed in one of the plurality of installation ports;

wherein each of the plurality of redundant powerplant units is located to receive hydrothermally heated fluid from at least one undersea hydrothermal source; and a power station coupled to receive electrical power from each of the plurality of redundant units.

1 1 . The system of claim 10 wherein each of the plurality of redundant powerplant units may include devices selected from the group consisting of an evaporator, a generator, a condenser and combinations thereof.

12. The system of claim 1 1 wherein the generator comprises a turbine coupled to an electric generator.

13. The system of claim 12 wherein the generator is housed in a pressure vessel.

14. The system of claim 13 wherein the power station is located above the surface of the water or in an offshore location.

15. An undersea hydrothermal energy transfer system comprising:

a first structure adapted to be installed in an undersea location;

a second structure adapted to be installed in an undersea location;

a third structure adapted to be installed in an undersea location;

a plurality of redundant evaporators installed in the first structure, wherein each of the plurality of redundant evaporators is coupled to receive hydrothermally heated fluid from at least one undersea hydrothermal source, and wherein the plurality of redundant evaporators produces a vapor flow;

at least one generator installed in the second structure coupled to receive the vapor flow from the plurality of evaporators so as to convert heat energy from the vapor flow into electrical energy;

a plurality of redundant condensers installed in the third structure wherein the plurality of condensers is coupled to an output of the at least one generator to receive a flow of spent vapor. 16. The system of claim 15 wherein the generator is housed in a pressure vessel.

17. The system of claim 15 wherein a plurality of shut off valves is connected between each of the plurality of condensers and the at least one generator. 18. The system of claim 15 wherein a plurality of shut off valves is connected between each of the plurality of evaporators and the at least one generator.

Description:
UNDERSEA HYDROTHERMAL ENERGY TRANSFER SYSTEM WITH

REMOVABLE REDUNDANT UNITS

Technical Field

The present invention relates to a hydrothermal power plant, more particularly, it relates to a deep water undersea hydrothermal energy transfer system with removable redundant units.

Background

With an ongoing need for affordable, sustainabie and green energy throughout the world, more resources are being directed to geothermal energy, and, in particular, hydrothermal energy. According to the US Department of Energy (DOE), the development of advanced exploration tools and technologies will accelerate the discovery and utilization of the U.S. Geological Survey’s estimated 30,000 MWe of hydrothermal resources in the Western United States.

A hydrothermal power generator requires fluid and heat to generate electricity. Conventional hydrothermal resources contain these components naturally. These hydrothermal systems can occur in widely diverse geologic settings, sometimes without clear surface manifestations of the underlying resource.

Deep water hydrothermal vents have been identified as a potential source of energy if they can be economically utilized. Hydrothermal vents are the result of seawater percolating down through fissures in the ocean crust in the vicinity of spreading centers or subduction zones (places on Earth where two tectonic plates move away or towards one another). The cold seawater is heated by hot magma and reemerges to form the vents. Seawater in hydrothermal vents may reach temperatures of over 700° Fahrenheit. Hof seawater in hydrothermal vents does not boil because of the extreme pressure at the depths where the vents are formed. This water is superheated by the magma and it picks up rare elements from deep within the earth in the process. A continuous flow of this superheated water escapes back into the ocean through hydrothermal vents, with hydrothermal fluid exiting the sea floor at typical velocities of between 1 and 5 meters per second (3 6-18 km/hr, or 2.25-1 1 mph).

One significant barrier to building deep water hydrothermal power plants are the difficulties of repairing, replacing and maintaining systems in a deep water environment. Current systems do not allow for redundant power components that can be removed and brought to the surface for repairs or maintenance. Further, there are no known systems providing parallel redundant power units that may receive thermally heated currents from an underwater hydrothermal vent to improve reliability.

As of this writing, the inventor is unaware of any operating industrial scale deep water hydrothermal power plant. In an attempt to remove the barriers to building a deep water hydrothermal power plant, the present disclosure provides a new and novel hydrothermal structure that overcomes technical difficulties in maintaining and operating the power plant.

Brief Summary of the Disclosure

This summary is provided to introduce, in a simplified form, a selection of concepts that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

Disclosed herein is an undersea hydrothermal energy transfer system including a structure having a number of underwater installation bays, the structure adapted to be easily installed in an undersea location. A number of redundant units is adapted to be installed and removed from bays on the structure. Each of the redundant units is located to receive hydrothermally heated fluid from at least one undersea hydrothermal source.

Brief Description of the Drawings

While the novel features of certain embodiments of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 schematically illustrates a functional block diagram of an example of a hydrothermal power plant with undersea redundant units. FIG. 2 schematically illustrates an example of an undersea thermal energy field coupled to a hydrothermal power generator system with redundant units oriented in a horizontal configuration.

FIG. 3 schematically illustrates an example of an undersea thermal energy field coupled to a hydrothermal power generator system with redundant units oriented in a vertical configuration.

FIG. 4 schematically illustrates an example of a redundant power plant unit used in a hydrothermal power generator system.

FIG. 5 schematically illustrates an example of a hydrothermal power generator system with redundant units positioned over an undersea thermal source.

FIG. 6 schematically illustrates a side view of an example of maintenance and replacement of a redundant unit in a hydrothermal power generator structure.

FIG. 6A schematically illustrates a top view of an example of an undersea hydrothermal energy transfer system featuring optional doors for enclosing unit installation bays.

FIG. 6B schematically illustrates an example of an undersea hydrothermal energy transfer system featuring optional valves for controlling flow to unit installation bays.

FIG. 7 schematically illustrates an example of a hydrothermal to mechanical energy converter.

FIG. 8 schematically illustrates an example of a hydrothermal to electrical energy converter.

FIG. 9 schematically illustrates a side view of an example of an undersea power generator system using power units arranged in series to receive hydrothermal fluids.

FIG. 10 schematically illustrates an alternate example of a redundant power plant unit used in a hydrothermal power generator system.

In the drawings, identical reference numbers identify similar elements or components. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not intended to convey any information regarding the actual shape of the particular elements and have been solely selected for ease of recognition in the drawings. Detailed Description

The following disclosure describes a hydrothermal energy transfer system with redundant units. Several features of methods and devices in accordance with example embodiments are set forth and described in the figures. It will be appreciated that methods and devices in accordance with other example embodiments can include additional features different than those shown in the figures. Example embodiments are described herein with respect to a method and apparatus directed to a hydrothermal energy transfer system with redundant units that are installed in a structure with multiple doors. However, it will be understood that these examples are for illustrating the principles, and that the invention is not so limited.

Unless the context requires otherwise, throughout the specification and claims which follow, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense that is as "including, but not limited to."

Reference throughout this specification to "one example," "an example embodiment," "one embodiment," "an embodiment" or combinations and/or variations of these terms means that a particular feature, structure or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases "in one example" or "in an example" in various places throughout this specification are not necessarily all referring to the same example embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Definitions

Generally, as used herein, the following terms have the following meanings when used within the context of hydrothermal power plants:

The articles“a” or“an” and the phrase“at least one” as used herein refers to one or more.

As used herein, "plurality" is understood to mean more than one. For example, a plurality refers to at least two, three, four, five, ten, 25, 50, 75, 100, 1 ,000, 10,000 or more.

"Obtaining" is understood herein as manufacturing, purchasing, or otherwise coming into possession of. Embodiments

Referring now to FIG. 1 , a functional block diagram of an example of a hydrothermal power plant with undersea redundant units is schematically shown. A hydrothermal power plant 10 includes an energy converter 14 coupled to an energy distribution apparatus 16 and an energy storage apparatus 12. The energy converter 14 receives energy from an undersea hydrothermal energy transfer system with redundant units 18. The undersea hydrothermal energy transfer system 18, in turn receives heat from an undersea hydrothermal source 20. It will be understood that the energy converter 14 need not include energy storage apparatus 12 or energy distribution apparatus 16, but these may be external to the hydrothermal power plant 10. Further, the hydrothermal power plant 10 may be located above the sea surface or even on an offshore land location. Further still, the energy converter 14 may be combined with the undersea power generator system 18 as described below. In that case, energy is transferred to a power distribution station located above the surface or on an offshore location.

Referring now to FIG. 2, an example of an undersea thermal energy field coupled to a hydrothermal power generator system with redundant units oriented in a horizontal configuration is schematically shown. One type of thermal energy source comprises a thermal energy field 22. The thermal energy field 22 may comprise one or more undersea hydrothermal energy sources 20. Each of the hydrothermal energy sources may also be coupled to a conduit 24 for fluidly transmitting thermally heated fluid to a main conduit, or plurality of conduits 26. The hydrothermal energy is then converted by a plurality of redundant powerplant units 128 installed in parallel or in series in a hydrothermal power generator system 418 and the converted hydrothermal energy is transmitted to a power distribution station 210 using power cables 21 1 , for example. The power distribution station 210 may be advantageously located above the sea surface 30 or at an offshore location. In this example, the hydrothermal power generator system 418 may be located to be supported horizontally on the seabed floor. Those skilled in the art having the benefit of this disclosure will understand that the various conduits may also include other components such as valves and the like. These have not been shown in every diagram to simplify the drawing and promote the understanding of the invention.

Referring now to FIG. 3, an example of an undersea thermal energy field coupled to a hydrothermal power generator system 318 with redundant units oriented in a vertical configuration is schematically shown. As described above, the thermal energy field 22 may comprise one or more undersea hydrothermal energy sources 20. Each of the hydrothermal energy sources may also be coupled to a conduit 24 for fluidly transmitting thermally heated fluid to a main conduit, or plurality of conduits 26. The hydrothermal energy is then converted by a plurality of redundant powerplant units 128 arranged in a parallel configuration and the converted hydrothermal energy is transmitted to the power distribution station 210, for example. In one example, the hydrothermal power generation system 318 may be installed by vertically lowering it to the seafloor 32 to rest on pylons or the like.

Referring now to FIG. 4, a stylized example of electrical generation is schematically illustrated. As detailed above, in one example, the redundant unit 128 includes an evaporator 922, a pressure vessel 924 and condenser 926. In order for the hydrothermal power generator system to generate electricity, there must be a pressure differential to create high-speed flow between the evaporator and the condensed. Due to the large pressures experienced at undersea depths, in some cases it may be necessary to encase the generators and condensers within a pressure vessel 924. Note that the condensers need not necessarily be enclosed in a pressure vessel 924 if the condenser tubes contained within them are able to withstand the pressure differential. In one useful example, the pressure vessel 924 includes electric power generating units including, for example a turbine 402 configured to drive an electric generator 404. The condenser 926, turbine 402, evaporator 922 and pump 406 operate as a heat engine. Hydrothermally heated fluids 414 enter the evaporator 22 to heat, for example, boiling tubes or coils (not shown) therein, cooler water is expelled as indicated by arrow 416. Similarly, condenser 926 receives heated fluid from the generator 404 and cools the fluid by drawing in cool water 410 and expelling used water. Each of the generator and condenser may be encased in a separate pressure vessel or share one. This is discussed further below with reference to FIG. 10.

Referring now to FIG. 5, an example of a hydrothermal power generator system with redundant units positioned over an undersea thermal source is schematically shown. In one example, the undersea hydrothermal energy transfer system 18 includes a structure 19 with a plurality of ports or doors 27 and/or valves, and a plurality of elongated supports 42. Installed in each of the ports 27 is one of a plurality of redundant units 28. The redundant units 28 may be installed in series and supported by mechanical supports, such as rails, for example. In order to generate hydrothermal power, the undersea hydrothermal energy transfer system 18 may be coupled to a main conduit 26 which receives hydrothermal flow from a hydrothermal energy field as described above. Wavey lines 37 indicate heated fluids rising from the hydrothermal energy field. In one example, each of the plurality of redundant units are positioned so as to receive thermal currents from the underwater hydrothermal energy field. Note that in other examples, the redundant unit 28 may comprise a single unit such as an evaporator which then transmits hydrothermally heated fluids to the power plant. Other configurations may be devised by those skilled in the art having the benefit of this disclosure.

Referring now to FIG. 6, a side view of an example of maintenance and replacement of a redundant unit in a hydrothermal power generator structure is schematically illustrated. The structure 19 directs the flow of hydrothermally heated fluids by operating as a flow channel as well as supporting the power units and providing port access. In the case where a redundant unit 28 needs repair or maintenance, it may be removed and brought to the surface for ease of repair and/or maintenance. In one example, another redundant unit 28 may be transferred through one of a plurality of ports or door openings 27 at the same time the redundant unit needing repair is removed. If the redundant unit needing repair is not replaced, the structure may include parallel doors for enclosing the empty space previously occupied by the redundant unit (as shown in FIG. 6A). Alternatively, conduits are piping from the redundant unit may be cut off from transmitting energy or vapor by closing a valve (as shown in FIG. 6B) so as not to interfere with operation of the other units still in place. Having performed the necessary maintenance on a removed redundant unit, the redundant unit may be returned to its original location or to any of the locations in the structure.

Referring now to FIG. 6A, a top view of the undersea hydrothermal energy transfer system is schematically shown featuring optional doors for enclosing unit installation spaces. In one example, an undersea hydrothermal energy transfer structure 19 includes a pair of access doors 52 and opposing side walls 54 for each of a plurality of installation bays 56. The pair of access doors 52 may be opened to allow installation of a redundant unit. The access doors 52 may be closed whether the installation bay is loaded with a redundant unit or left empty. Keeping each installation bay 56 enclosed allows for contained flow of hydrothermally heated fluids through the undersea hydrothermal energy transfer structure 19. In other cases, valves may be used as described herein. Alternatively, a single door may be used to open and close the bay. In another alternative, the sides of the unit may serve as walls for the bay.

Still referring jointly to FIG. 6 and FIG. 6A, having described the components of an undersea power generator system, it is now considered important to the understanding of some advantages of the invention to describe an example of a maintenance procedure enabled by the structure disclosed herein. In one example, should a redundant unit 28 require maintenance or replacement, the redundant unit may be removed by pulling it from the installation bay 56 using a mechanical system powered or actuated by cables going to a surface vessel, underwater motors or underwater vehicles manned or unmanned. The redundant unit to be replaced may be rolled out in a continuous motion and simultaneously replace by another redundant unit, if desired. Once the redundant unit has been cleared from the structure, it can then be lifted to the surface where maintenance activities or repairs can be made much more easily than attempting repairs underwater. When the repairs or maintenance activities are complete, the power unit may be replaced by reversing the procedure described herein above. In one example, the redundant units comprise evaporators which convey heated vapors directly to a power plant above the sea surface.

One common cause of maintenance is scaling that may be deposited on boiler tubes, for example. Such scaling can be routinely removed, but this is much easier to do on the surface, as opposed to performing an underwater operation. Further, since the units are redundant, while one unit is being maintained the hydrothermal power plant continues to operate using the remaining units.

Referring now to FIG. 6B an example of an undersea hydrothermal energy transfer system featuring optional valves for controlling flow to unit installation bays is schematically illustrated. As described above, the thermal energy field 22 may comprise one or more undersea hydrothermal energy sources 20 that fluidly transmit thermally heated fluid to a main conduit, or plurality of conduits 26. Instead of doors or ports, the installation bays may be coupled to valves 1050 which control the flow of hydrothermal fluid to units installed in the bays.

Referring now to Fig. 7, an example of a hydrothermal to mechanical energy converter is schematically illustrated. As described above, a hydrothermal power plant 10 may advantageously include an energy converter 14 (see FIG. 1 ). In one example the energy converter can comprise a hydrothermal to mechanical energy converter 14A including an evaporator 922 coupled to receive hydrothermally heated fluids 414 where the evaporator is coupled to motivate driver 1060. Driver 1060 may be a turbine motor, for example that outputs mechanical power 1062. The hydrothermal to mechanical energy converter 14A may employ any of the plurality of thermal energy cycles including engines employing Carnot heat engine cycle theories including a Rankine closed cycle systems using external heat sources and two phase working fluids, a Stirling cycle engine, an Erickson cycle engine, a Stoddard engine and the like.

Referring now to Fig. 8, an example of a hydrothermal to electrical energy converter is schematically illustrated. As described above, a hydrothermal power plant 10 may advantageously include an energy converter 14B. In one example the energy converter can comprise a thermoelectric generator 1924 which receives heat from a heat source such as an evaporator 922. The thermoelectric generator 1924 outputs electrical power 10 Such converters include systems employing the thermoelectric effect, also known as the Seebeck effect. The thermoelectric effect is based on the electric potential produced in thermoelectric materials by the temperature difference.

Referring now to FIG. 9, a side view of an example of an undersea hydrothermal energy transfer system is schematically illustrated. Installed in each port 27 is a redundant powerplant unit 928. Each redundant powerplant unit 928 may comprise a plurality of devices including at least one evaporator 922, a generator 924, and at least one condenser 926. Other components necessary for the generation of electricity may be included in accordance with conventional design principles. For example, the generator 924 may include a turbine coupled to an electric generator as is used in, for example, geothermal power plants (see, for example, FIG. 4). Each redundant unit 928 may preferably be substantially identical, thereby providing redundancy should any of the other units fail. A power distribution station 210 may preferably be placed proximate the structure 19 in order to receive electrical power from each of the plurality of redundant units 928. Power may be transmitted to the power distribution station 210, which is stationed above the surface of the water 30, by cables, for example, as represented by transmission arrows 950. In this example, power distribution station 210 need not contain an energy converter, since the energy conversion is done by the redundant units. Instead the power distribution station 210 may include other components common in power distribution and storage such as batteries, power transformers and the like. Note that this example shows an optional configuration for the structure which is embedded below the surface 32 of the seabed using foundation elements 917 and supports 914.

Referring now to FIG. 10, an alternate example of a redundant power plant unit used in a hydrothermal power generator system is schematically illustrated. In one example each powerplant comprises a plurality of evaporators 922 which are fluidly coupled by conduits 1076, valves 1050 and conduit 1070 to transmit vapor to power a generator 924, as for example a turbine generator. The generator 924 transmits electrical energy to a power distribution station 210 as described above. After passing through the generator 924, the vapor fluidly flows into a plurality of condensers 926. In one useful example, the redundant unit may employ three evaporators 922, three condensers 926 and the single generator 924.

In one example, the plurality of evaporators 922 may be coupled by conduit 1076 to a valve 1050. When the valve is opened, a high-pressure vapor flow moves through conduit 1070 and impinges on the turbine generator so as to spin the generator to create electricity. If one of the evaporators 922 needs to be removed for maintenance, the valve 1050 may be closed, thereby allowing the other evaporators to continue operation in combination with the turbine generator and condensers. Similarly, spent vapor output from the turbine generator 924 is transmitted through conduit 1072 through another set of valves 1050 to the plurality of condensers 926. If a condenser needs to be removed for maintenance or other reasons, the valve 1050 coupled to it may be closed without substantially impacting operation of the hydrothermal powerplant comprising the plurality of evaporators, turbine generator and condensers.

Still referring to FIG. 10, the plurality of evaporators 922 may be themselves mounted in a structure similar to the structures described hereinabove with reference to FIG. 5 or FIG. 9 . The plurality of condensers 926 may also be housed in a similar structure. Further, the generator 924 may be housed together with other generators in a similar structure.

The evaporators, condensers and generators may be on different maintenance schedules. The condensers and evaporators may need to be pulled for maintenance more frequently than the generators. For example, while a generator may need maintenance on an annual basis, the other units may need monthly maintenance.

Having fully described the components of a deep water hydrothermal power plant, it is considered instructive to the understanding of the principles disclosed herein to describe an example of operation of the hydrothermal power plant. In one example, thermal currents from main conduit 26 (see FIG. 2, for example) rise to heat the evaporators 922. The evaporators 922 subsequently provide energy to motivate the generator 924, as by, for example causing a turbine to rotate. The rotating turbine is coupled to an electric generator which provides electric power. The electric power is then transmitted to the power distribution station 210 as indicated by arrows 950. The condensers 926 cooperate in a conventional manner with the evaporator to operate as a heat engine, as in a Rankine heat engine or the like.

The invention has been described herein in considerable detail in order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles of the present invention, and to construct and use such exemplary and specialized components as are required. However, it is to be understood that the invention may be carried out by different equipment, and devices, and that various modifications, both as to the equipment details and operating procedures, may be accomplished without departing from the true spirit and scope of the present invention.